 
 (def ^:dynamic *cli4clj-line-sep* (System/getProperty "line.separator"))
 
+(def print-exception-trace (atom false))
 
 (defn cli-repl-print
   "The default repl print function of cli4clj only prints non-nil values."

  {:allow-eval false
   :cmds {:h :help
          :? :help
          :q :quit}
   :eval-factory create-cli-eval-fn
   :help-factory create-cli-help-fn
   :help-cmd-entry-delimiter *cli4clj-line-sep*

   Otherwise, the string representation of the passed argument is printed to stderr."
  (fn [arg] (instance? Exception arg)))
(defmethod print-err-fn true [arg]
  (if @print-exception-trace
    (.printStackTrace arg)
    (println-err (.getMessage arg))))
(defmethod print-err-fn false [arg]
  (println-err (str arg)))

